package main

import (
	"fmt"
	"os"
)

type Data struct {

}

// toString()
func (self Data) String() string {
	return "data"
}
func main(){
	fmt.Printf("hello world\n")
	fmt.Println("hello world",2,"string")

	fmt.Printf("num %d %s %v \n",3,"2",3.234)
	str := fmt.Sprintf("float %f",3.14)
	fmt.Print(str)

	fmt.Fprintln(os.Stdout,"A\n")

	fmt.Printf("%v \n",Data{})
}
